About this article
Medically reviewed- Written by
- Dr Paul Watson
- Medically reviewed by
- Dr Han Simpson
- Published
- July 2, 2026
- Medical review date
- September 8, 2026
- Evidence searched through
- September 8, 2026
- Next review due
- September 8, 2027
- Intended audience
- General Readers & Patients
- Geographic scope
- Worldwide
- Conflicts of interest
- None declared.
- Funding
- Website Owner
- Report a correction
- Report an error or editorial concern
- Medical disclaimer
- Read the medical disclaimer
TB-500 is one of the most widely discussed research peptides, and one of the questions people ask most often is how to calculate the correct concentration after adding bacteriostatic (BAC) water. This is why we have created our very own TB-500 Dosage Calculator.
Whether you’re reconstituting a 2mg, 5mg or 10mg vial, understanding the relationship between BAC water, peptide concentration and insulin syringe units makes calculating doses much easier.
This TB-500 dosage calculator explains the mathematics behind peptide reconstitution using simple formulas, concentration tables, mixing charts and worked examples. Rather than focusing on a single dilution, this guide shows you how to calculate virtually any TB-500 concentration.
In this guide you’ll learn:
- How to calculate TB-500 doses
- How much BAC water to use
- Concentration calculations
- Mixing charts for 2mg, 5mg and 10mg vials
- U100 insulin syringe conversions
- Worked dosage examples
- Frequently asked questions
Educational notice: This guide explains the mathematics behind peptide dilution and reconstitution. It does not recommend any specific dosage or treatment protocol. TB-500 is commonly sold as a research peptide, and product quality, formulation and intended use may vary between manufacturers.
TB-500 Dosage Calculator
Calculating TB-500 doses is easier than many people expect.
Every calculation follows the same four steps:
- Decide how much BAC water to add.
- Calculate the concentration of the finished solution.
- Calculate the injection volume required.
- Convert the volume into U100 insulin syringe units.
The formulas remain exactly the same whether you’re mixing a 2mg, 5mg, or 10mg vial.
Step 1 – Calculate Concentration
Concentration = Total Peptide ÷ BAC Water Added
Example:
5mg ÷ 2mL
= 2.5mg per mL
Step 2 – Calculate Injection Volume
Desired Dose ÷ Concentration = Injection Volume
Example:
Desired dose:
1mg
1 ÷ 2.5
= 0.40mL
Using a U100 insulin syringe:
0.40mL = 40 units
Once you understand these two formulas, you can calculate virtually any TB-500 dilution.
What Is TB-500?
TB-500 is a synthetic peptide based on a naturally occurring region of Thymosin Beta-4 (TB4), a protein involved in tissue repair, cell migration and wound healing.
Unlike full-length Thymosin Beta-4, TB-500 is a shorter peptide fragment that has become popular within research settings due to its stability and ease of manufacture.
TB-500 is commonly supplied as a freeze-dried (lyophilised) powder and must be mixed with bacteriostatic water before use.
Common vial sizes include:
- 2mg
- 5mg
- 10mg
Because each vial size contains a different amount of peptide, understanding concentration is essential before calculating injection volumes.
Why Use a TB-500 Dosage Calculator?
A dosage calculator removes guesswork.
Instead of trying to memorise syringe conversions, you can quickly determine:
- Peptide concentration
- Injection volume
- Syringe units
- BAC water ratios
This makes calculations consistent regardless of which vial size you purchase.
TB-500 BAC Water Calculator
The table below shows the concentration produced by the most commonly used BAC water volumes.
2mg TB-500 Vial
| BAC Water | Concentration | mg per 10 Units |
|---|---|---|
| 1mL | 2mg/mL | 0.20mg |
| 2mL | 1mg/mL | 0.10mg |
| 2.5mL | 0.8mg/mL | 0.08mg |
| 3mL | 0.67mg/mL | 0.067mg |
| 5mL | 0.4mg/mL | 0.04mg |
5mg TB-500 Vial
| BAC Water | Concentration | mg per 10 Units |
|---|---|---|
| 1mL | 5mg/mL | 0.50mg |
| 2mL | 2.5mg/mL | 0.25mg |
| 2.5mL | 2mg/mL | 0.20mg |
| 3mL | 1.67mg/mL | 0.167mg |
| 5mL | 1mg/mL | 0.10mg |
10mg TB-500 Vial
| BAC Water | Concentration | mg per 10 Units |
|---|---|---|
| 1mL | 10mg/mL | 1mg |
| 2mL | 5mg/mL | 0.50mg |
| 2.5mL | 4mg/mL | 0.40mg |
| 3mL | 3.33mg/mL | 0.333mg |
| 5mL | 2mg/mL | 0.20mg |
These tables provide a quick way to estimate how much peptide is delivered for every 10 units on a U100 insulin syringe.
How Much BAC Water Should You Use?
There isn’t one universally correct dilution for TB-500.
Instead, most people choose an amount of BAC water that makes measuring their intended injection volume simple and repeatable.
| BAC Water | Advantages |
|---|---|
| 1mL | Highest concentration and smallest injection volume |
| 2mL | Simple calculations with moderate injection volume |
| 2.5mL | Balanced concentration and easy conversions |
| 3mL | Lower concentration for fine dose adjustments |
| 5mL | Largest injection volume and easiest measurement for very small doses |
Adding more BAC water does not change the total amount of peptide inside the vial.
It simply changes how concentrated the solution becomes.
TB-500 Mixing Charts
The following charts show how much peptide is delivered at common syringe measurements.
2mg Vial Mixed with 2mL BAC Water
| Syringe Units | TB-500 |
|---|---|
| 5 | 0.05mg |
| 10 | 0.10mg |
| 20 | 0.20mg |
| 30 | 0.30mg |
| 40 | 0.40mg |
| 50 | 0.50mg |
| 60 | 0.60mg |
| 70 | 0.70mg |
| 80 | 0.80mg |
| 90 | 0.90mg |
| 100 | 1mg |
5mg Vial Mixed with 2mL BAC Water
| Syringe Units | TB-500 |
|---|---|
| 5 | 0.125mg |
| 10 | 0.25mg |
| 20 | 0.50mg |
| 30 | 0.75mg |
| 40 | 1mg |
| 50 | 1.25mg |
| 60 | 1.50mg |
| 70 | 1.75mg |
| 80 | 2mg |
| 90 | 2.25mg |
| 100 | 2.5mg |
10mg Vial Mixed with 2mL BAC Water
| Syringe Units | TB-500 |
|---|---|
| 5 | 0.25mg |
| 10 | 0.50mg |
| 20 | 1mg |
| 30 | 1.5mg |
| 40 | 2mg |
| 50 | 2.5mg |
| 60 | 3mg |
| 70 | 3.5mg |
| 80 | 4mg |
| 90 | 4.5mg |
| 100 | 5mg |
These are among the most commonly used mixing ratios because they produce simple, easy-to-calculate concentrations.
Worked Examples
The following examples demonstrate how to calculate injection volumes using different vial sizes.
Example 1 – 5mg Vial
- Vial size: 5mg
- BAC water: 2mL
- Desired dose: 1mg
Concentration:
2.5mg/mL
Calculation:
1 ÷ 2.5 = 0.40mL
Injection: 40 units
Example 2 – 10mg Vial
- Vial size: 10mg
- BAC water: 2.5mL
- Desired dose: 2mg
Concentration:
4mg/mL
Calculation:
2 ÷ 4 = 0.50mL
Injection: 50 units
Example 3 – 2mg Vial
- Vial size: 2mg
- BAC water: 1mL
- Desired dose: 0.5mg
Concentration:
2mg/mL
Calculation:
0.5 ÷ 2 = 0.25mL
Injection: 25 units
Which Vial Size Is Best?
TB-500 is commonly available in 2mg, 5mg and 10mg vials, but the best option depends on your intended use and how frequently you’re preparing fresh solutions.
Smaller vials may be more convenient if you prefer to mix fresh batches more often, while larger vials can reduce the number of times reconstitution is required. Regardless of vial size, the calculation method remains exactly the same—the only difference is the starting amount of peptide.
Understanding these calculations makes it easy to adjust concentrations, compare vial sizes and accurately measure doses using a U100 insulin syringe.
How to Reconstitute TB-500
Once you’ve decided how much bacteriostatic (BAC) water to use, the next step is reconstituting your TB-500 vial.
Reconstitution is simply the process of adding sterile bacteriostatic water to the freeze-dried peptide powder, creating a solution that can be accurately measured using a U100 insulin syringe.
Although the process is straightforward, following good sterile technique helps minimise contamination and maintain the quality of the peptide solution.
Equipment You’ll Need
Before reconstituting TB-500, gather the following equipment:
- TB-500 peptide vial
- Bacteriostatic (BAC) water
- Sterile mixing syringe
- U100 insulin syringes
- Alcohol swabs
- Clean work surface
- Refrigerator for storage
Before opening either vial, inspect them carefully. The TB-500 powder should appear dry and intact, while the BAC water should be clear and free from particles.
Step-by-Step TB-500 Reconstitution Guide
Step 1 – Wash Your Hands
Wash your hands thoroughly using soap and warm water before handling any equipment.
Maintaining a clean workspace helps reduce the risk of contamination.
Step 2 – Clean the Rubber Stoppers
Use separate alcohol swabs to disinfect:
- the TB-500 vial
- the BAC water vial
Allow both stoppers to air dry completely before inserting a needle.
Step 3 – Draw the BAC Water
Using a sterile syringe, withdraw your chosen amount of BAC water.
Common amounts include:
- 1mL
- 2mL
- 2.5mL
- 3mL
- 5mL
The amount you choose determines the final concentration of the solution but does not change the total amount of peptide in the vial.
Step 4 – Add the BAC Water Slowly
Insert the needle through the stopper and slowly inject the BAC water down the inside wall of the vial.
Avoid spraying the water directly onto the freeze-dried peptide cake.
Injecting slowly helps minimise foaming and allows the peptide to dissolve naturally.
Step 5 – Allow the Powder to Dissolve
Most TB-500 vials dissolve within a few minutes.
Rather than shaking the vial, gently swirl or rotate it until the solution becomes completely clear.
If tiny particles remain, allow the vial to rest for several more minutes before swirling again.
Why You Shouldn’t Shake TB-500
Although TB-500 is relatively stable once reconstituted, vigorous shaking can create unnecessary bubbles and foam.
Gentle swirling is generally considered best practice because it allows the powder to dissolve evenly without excessive agitation.
Choosing the Right Amount of BAC Water
One of the most frequently asked questions is:
“How much BAC water should I use for TB-500?”
There isn’t a universally accepted answer.
The best dilution depends on the concentration you prefer and how easy you want your injections to be to measure.
| BAC Water | Best For |
|---|---|
| 1mL | Highest concentration and smallest injection volume |
| 2mL | Simple calculations and popular choice |
| 2.5mL | Balanced concentration and straightforward syringe conversions |
| 3mL | Lower concentration for easier fine adjustments |
| 5mL | Maximum measuring precision for smaller doses |
If you’re unsure where to begin, 2mL is often chosen because it produces simple, easy-to-calculate concentrations across all common TB-500 vial sizes.
Does More BAC Water Make TB-500 Weaker?
No.
Adding additional BAC water does not reduce the amount of peptide inside the vial.
Instead, it simply spreads the peptide across a larger volume of liquid.
For example:
A 5mg vial always contains 5mg of TB-500.
Whether you mix it with:
- 1mL
- 2mL
- 3mL
- 5mL
the vial still contains exactly 5mg.
The only difference is the amount of liquid required to deliver a specific dose.
Common TB-500 Mixing Mistakes
Avoiding these common mistakes will help ensure accurate calculations and good sterile technique.
Using Tap Water
Only use bacteriostatic water or sterile water intended for injection.
Tap water should never be used.
Injecting BAC Water Too Quickly
Introducing the water slowly reduces foaming and allows the peptide to dissolve more evenly.
Shaking the Vial
There’s no need to shake TB-500.
Gentle swirling is sufficient.
Forgetting to Clean the Stopper
Always disinfect the rubber stopper before every needle entry.
This simple step helps reduce contamination.
Reusing Syringes
Always use a new sterile syringe and needle for every withdrawal.
Reusing needles increases contamination risk and can make injections more uncomfortable.
Forgetting to Recalculate Doses
Changing the amount of BAC water changes the concentration.
Every time you choose a different dilution, you’ll need to calculate your syringe units again.
How to Store Reconstituted TB-500
Proper storage helps preserve the quality of the solution after mixing.
General recommendations include:
- Refrigerate between 2°C and 8°C
- Keep away from direct sunlight
- Avoid excessive heat
- Do not freeze unless specifically recommended by the manufacturer
- Store upright whenever possible
- Inspect the solution before every use
If the solution becomes cloudy, develops unexpected particles or changes appearance, it should not be used.
TB-500 Dosage Calculation Tips
Before calculating any injection, remember these simple rules.
✓ More BAC water = lower concentration
✓ Less BAC water = higher concentration
✓ The total amount of peptide never changes
✓ Always calculate concentration before injection volume
✓ Double-check syringe measurements before every injection
Once you understand these principles, calculating TB-500 doses becomes straightforward regardless of vial size.
Frequently Asked Questions
What is TB-500?
TB-500 is a synthetic peptide based on a region of the naturally occurring protein Thymosin Beta-4. It is commonly supplied as a freeze-dried powder that requires reconstitution before use.
How much BAC water should I use for TB-500?
There is no single correct amount.
Common mixing volumes include 1mL, 2mL, 2.5mL, 3mL and 5mL, depending on the concentration you wish to achieve.
Can I use sterile water instead of BAC water?
Sterile water can be used for reconstitution, but because it contains no preservative it is generally intended for immediate or short-term use. BAC water is commonly preferred for multi-dose vials because it contains a bacteriostatic preservative.
Can I add more BAC water later?
Yes, but adding more BAC water changes the concentration of the solution.
If you do this, you’ll need to recalculate future injection volumes.
Does more BAC water reduce the strength of TB-500?
No.
The total amount of peptide inside the vial remains exactly the same.
Only the concentration changes.
How long does TB-500 last after mixing?
The usable life of a reconstituted vial depends on the manufacturer, storage conditions and the type of water used. Always follow the manufacturer’s recommendations and discard the solution if contamination is suspected.
Can I freeze TB-500?
Unless the manufacturer specifically recommends freezing, reconstituted TB-500 is generally stored in a refrigerator rather than a freezer.
What syringe should I use?
Most peptide users choose a U100 insulin syringe because it allows accurate measurement of small injection volumes.
Can I calculate doses for any TB-500 vial?
Yes.
The same formulas apply regardless of vial size.
Simply calculate the concentration first:
Concentration = Total Peptide ÷ BAC Water Added
Then calculate the injection volume:
Desired Dose ÷ Concentration
What’s the difference between TB-500 and Thymosin Beta-4?
TB-500 is a synthetic peptide based on an active region of the naturally occurring protein Thymosin Beta-4. Although the two are closely related, they are not identical molecules, and products marketed under these names may differ. Always check the manufacturer’s documentation to understand exactly which peptide your product contains.
Can I use the same calculator for other peptides?
The mathematics behind peptide reconstitution is the same for many lyophilised peptides. However, because vial sizes and concentrations vary, it’s best to use a calculator designed specifically for the peptide and vial strength you’re using.
If you’re also researching BPC-157, our BPC-157 Dosage Calculator includes concentration tables, BAC water mixing charts, and syringe conversion guides using the same calculation methods explained in this article. Similarly, our Glow Dosage Calculator.
Final Thoughts
A TB-500 dosage calculator takes the guesswork out of peptide reconstitution by helping you calculate concentrations, injection volumes and syringe units accurately.
Whether you’re mixing a 2mg, 5mg or 10mg vial, the principles remain the same. The total amount of peptide never changes—only the concentration of the solution and the volume required for each injection.
By using the concentration formulas, BAC water mixing charts and syringe conversion tables throughout this guide, you can confidently calculate virtually any TB-500 dilution while gaining a better understanding of peptide reconstitution as a whole.
As your peptide knowledge grows, these same calculation methods can also be applied to many other lyophilised peptides, making this guide a useful reference whenever you need to determine concentrations, compare vial sizes or prepare a new peptide solution.